If I understand your question correctly, you are concerned because the welders are depositing the required weld size using more passes than were used when the welding procedure was qualified.

If there is a concern with notch toughness, heat input is an issue. High heat input results in larger coarser grains which have low impact toughness. Low heat input results in fine grains and tougher material.

A groove weld of a given size will have finer grain size if the heat input is minimized by depositing smaller weld beads, but more weld beads are required to completely fill the groove. The same groove (same size weld) will have a higher heat input, larger (coarser) grain size if the welders deposit large weld beads, but it will take fewer beads to completey fill the groove.

Thus the groove weld that is filled with 30 weld beads will have better toughness than the same groove weld filled with only 15 weld beads.

I hope this helps you to resolve your conflict.

Best regards - Al